Vladimir Kosygin wanted to be a doctor, but instead became an agent for the KGB to appease his uncle, who raised him. Stationed at the Rezidentura in Washington, DC, he worked closely with Arkady Ivanovich, and was friendly with Nina, a colleague and FBI informant for counter intelligence agent Stan Beeman. It is implied by one of Nina's co-workers that Vlad harbored romantic feelings for her, but knew she was "out of his league."
Vlad is kidnapped by a team of FBI and CIA agents, who originally intended to kill his boss Arkady on an his afternoon jog (Arkady injures his hand and Vlad goes running alone). Despite scant evidence, Stan is convinced his missing partner Chris Amador has been kidnapped by the KGB, and hopes to trade Vlad for him. As the staff at the Rezidentura do not have Amador and are unaware of his whereabouts, Stan's attempts to negotiate a trade go nowhere. When Amador's dead body is discovered, an enraged Stan shoots Vlad in the back of the head.
Nina grows to believe Stan murdered Vlad, although he repeatedly denies it. This damages her trust in Stan's intentions. Vlad's death at Stan's hands is a significant motivating factor for her confessing treason to Arkady, and offering to turn on Stan as a double agent.
Arkady later tells Gaad that Vlad was never cut out to be a spy, and at the time of his death was likely a year away from "washing out:" leaving the KGB to pursue his dreams of becoming a doctor.